Submerged circuit controller



Jan. 21, 1930. G. B. -SAYRE 1,744,508

SUBMERGED CIRCUIT CONTROLLER Filed NOV. 29, 1924 Patented Jan. 21, 193i GORDON B. SAYRE, OF SYRACUSE, NEV] YORK SUBMERGED CIRCUIT CONTROLLER Application filed. November 29, 1924.

My invention relates to improvements in a submerged circuit controller of a kind in which a thermal unit is submerged in a medium, the temperature of which governs the action of the thermal unit, and the latter controls an electric circuit. My invention is intended to provide a simple and efficient circuit controller of the kind specified, in which the thermal unit normally holds an electric circuit operative, butwhich has a fusible element so that when the temperature of the submerged medium rises to a predetermined point, the softening of the fusible material allows a part of the unit to change its position and thereby render the electric circuit inoperative. My invention is intended further to produce a structure of this kind in which the thermal unit when it has acted as above outlined, leaves the circuit inoperative, but which when the submerging medium has cooled, can be turned but only by extraneous means and not automatically, so as to reinstate the circuit. This latter feature is important because by having the circuit left temporarily inoperative by the action of the thermal unit, no bad results can occur through the restoration of the circuit too soon.

My invention is further intended to provide a submerged thermal circuit controller in which the submerging medium may be the part heated by t 1e circuit, or may be connected with a larger body which is to be kept at a constant temperature, and the submerging medium will therefore be of substantially the same temperature as that of the larger body to be controlled, so that when the thermal unit acts to render the circuit inoperative, it obviously can be made to cut out the heat supply of the larger body in any of the well-known ways. My invention is also intended to include an electric heating element directly in the submerging medium and in the circuit to be controlled, so that when the flow of current for any reason gets too high in the circuit,

Serial No. 752,897.

the heating element responsive to the overcharge f the circuit, will through the heated o subinerging medium, act on the thermal unit to render the circuit inoperative.

My invention is further intended to produce a thermal unit in the form of a cartridge having a fusible filler acting to normally hold a plunger in place and control the circuit through the action of the plunger, and to mount the cartridge in such a way that its position will be indicated on the exterior of the casing so as to indicate whether the circuit is operative or not, and to provide an exterior means for turning the cartridge back into position to restore the circuit after it has been automatically destroyed.

These and other advantages of the invention will appear more clearly from the description which follows.

E- ference is to be had to the accompanying drawings forming a part of this specification, in which similar reference characters indicate corresponding parts in all the views.

Figure 1 is a sectional elevation of a device embodying my invention.

Figure 2 is a cross section of the structure shown in Figure 1.

Figure 3 is a cross section of a slightly different structure in which an electric heating element is contained in the casing.

Figure 4 is a sectional elevation of the structure shown in Figure 3 and illustrating a conventional circuit controlled by the parts.

Figure 5 is an exterior view of the casing as shown in both Figures 2 and l, and

Figure 6 is a longitudinal section of the cartridge forming a part of my improved circuit controller.

The drawings are by way of example, and show a means of carrying the invention into effect, but structurally the drawings are not important, as my invention has very wide application which will be apparent from the following description.

The basis the invention is a thermal cartridge which I do not here claim specifically but which is particularly applicable to this invention. This cartridge comprises a tubular shell having closed ends 11, a fusible filler 12, and a plunger 13' movable lengthwise through the ends 11 and having an abutment 14 held in normal position by the filler 12 when the latter is cool. I use the term fusible as implying any material which will soften under the rise of temperature so as to permit the movement of the parts 13 and 14.

This cartridge or thermal unit is submerged in a medium contained in a suitable casing 15, and can be mounted in any convenient way but preferably so that it can be turned or reversed. As illustrated in Figure 1 the plunger 13 holds a spring terminal 16 of one wire 17 of an electric circuit against a contact screw 18 on a post 19, the latter connecting with a second wire 20 of the circuit to be controlled. The terminals, it will be understood, are submerged in the medium which fills the casin 15, and the current might be used to heat the medium in the casing 15, or the casing can be placed so that the temperature of its contained submerging medium will be substantially that of another body of liquid whose temperature is to be controlled. For instance, the casing might be connected by circulation pipes 21 and 22 with such liquid or other body.

It will be noticed that when the temperature of the submerging medium rises to a certain point, the softening of the material 12 will permit the spring tension of the member 16 to push back the plunger 13, thus breaking and making inoperative the electric circuit of which the terminal forms a part; and it will be further observed that the circuit will remain inoperative or broken until it is restored by extraneous means. For in stance, if the plunger 13 has moved back under the impact of the spring 16, the circuit will obviously remain broken, but after the medium, and consequently the material 12 has cooled, and the filling material hardened, then the cartridge 10 can be reversed and the plunger 13 will'push the terminal 16 into contact with the screw 18, thereby closing the circuit.

As a convenient means of accomplishing this result I have shown the cartridge 10 provided with a transverse rod 23 having a finger piece 24 by which it may be turned, and the rod can be extended out through a gland 25. Thus by grasping the finger piece, the cartridge 10 can be turned in such a way as to restore the circuit when desired, and the car tridge can be used over and over for a long period of time.

As shown in Figure 5, the casing 15 may be marked on the outer side to show whether the current is on or oil", and the position of the finger piece or key at with reference to said markings will facilitate the easy reading of the device.

As shown in Figures 3 and A I have illustrated another application of the invention and a slight modification thereof, in which the thermal unit is shown as controlling a circuit 26 which is the standard ignition circuit of many automobile manufacturers, and in order that the application of the invention may be understood, it is pointed out that 27 represents the battery, 28 the ignition switch, 29 the induction coils, and 30 the distributor. This circuit 26 is shown connected with the terminals 31 and 32 inside the casing 15. The circuit also includes a heating device for heating the submerging medium in the casing 15, which heating device can conveniently be a resistance element 33 connected between the post terminal 31 and a second post 34: having a contact screw 35 engaged by a spring terminal 36 in the circuit. This arrangement it will be seen is shown precisely as in Figure 1, except that the heating element 33 is included in the circuit. The cartridge 10 is arranged as already set forth exceptthat the rise of temperature in the submerging medium is caused by the resistance 33 instead of any other source of heat. Such a device can be conveniently included in a circuit, as for instance 26, and the resistance element 33 has a really beneficial efiect as a brake 0r stabilizer of the current, and when the current is normal there is not sufficient heat generated in the element to afi ect the thermal unit, but if a substantial overload occurs for any reason, the temperature of the heating element will raise the temperature of the submerging medium until as the danger point is reached, the thermal unit will act as already described to break the circuit and leave it inoperative. It will be readily seen that this arrangement works out very nicely as the action is not quick and spasmodic, but the heating of the submerging medium will be effected gradually as the flow of current rises until when the danger point is reached the break occurs and the circuit is left inoperative until reinstated as described.

It will be noted that the time period required for operating the circuit controller is inverse to the strength of current, that is with low current the time would be long and with high current the time would be short. This is obvious for the reason that the low current would raise the temperature of the submerging liquid slower than would the higher current.

I claim 1. A structure of the kind described, comprising a pair of circuit terminals movable to open and close a circuit, a submerging medium, a thermal unit in the submerging me dium and responsive solely to the tempera ture at said medium, said thermal unit bemg disposed to act on the aforesaid terminals, and means exterior of the submerging medium for shifting the position of the thermal unit with relation to the circuit terminals.

2. A submerged circuit controller, comprising a bath of submerging liquid, a pair of terminals arranged in said bath and act ing to open and close a circuit, a thermal unit in the said bath responsive solely to the temperature of the bath and disposed to act upon the terminals, and means exterior of the bath for changing the position of the thermal unit.

A structure of the kind described, comprising a tank containing a submerging liquid, a pair of circuit terminals extending into the tank and movable to open and close a circuit, a thermal unit in the tank responsive solely to the temperature of the submerging medium and acting upon the terminals, means exterior of the tank for changing the position of the thermal unit, and an indicator on the outside of the tank showing the position of the thermal unit with relation to the terminals.

4. A structure of the kind described, comprising a tank containing a submerging medium, a pair of electric terminals extending into the tank and normally out of contact, a cartridge in the tank containing a material softened by the rise of temperature of the submerging medium, a plunger and rod held normally by said softening material and acting against one of the terminals to close the circuit, and means exterior of the tank for shifting the position of the cartridge.

5. A thermal circuit controller, comprising a pair of normally open circuit terminals, a submerging medium, a cartridge in the submerging medium and responsive solely to the change of temperature in said medium, said cartridge containing fusible material, a plunger movable in said cartridge and positioned by the fusible material when unsolitened, said cartridge being disposed to have the plunger act against one of the terminals, and means exterior of the submerging medium for shifting the position of the cartridge.

6. A submerged circuit controller, comprising a submerging medium, a pair of electric terminals, a heating element in the submerging medium, said terminals and heating element being adapted to complete a circuit, and a thermal unit in the submerging medium responsive solely to the rise of temperature in said medium and acting to position the aforesaid terminals, said thermal unit being arranged exterior to the circuit of said terminals and not afiected by the current flowing thru said terminals.

7 In combination, a submerging medium, a resistance unit in said submerging medium, a circuit breaker, said resistance unit and circuit breaker being adapted to complete a cir- November, 1924.

GORDON B. SAYRE. 

